Genome-wide expression profiling of ARABIDOPSIS RESPONSE REGULATOR 7(ARR7) overexpression in cytokinin response
Genome-wide expression profiling of ARABIDOPSIS RESPONSE REGULATOR 7(ARR7) overexpression in cytokinin response
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DOI：
10.1007/s00438-006-0177-x
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发表时间：
2007-02-01
影响因子：
3.1
通讯作者：
Kim, Jungmook
中科院分区：
文献类型：
--
作者：
Lee, Dong Ju;Park, Jin-Young;Kim, Jungmook
细胞分裂素双组分信号系统中除ARR4外，A型ARR对细胞分裂素信号传导起到负调节作用，但A型ARR调节细胞分裂素信号传导的分子机制仍不清楚。为了深入了解 A 型 ARR 在细胞分裂素反应中的分子功能，我们通过使用 Affymetrix 全基因组阵列研究 ARR7 过表达对细胞分裂素调节基因表达的影响，试图找到在 A 型 ARR 蛋白下游起作用的成分。为了检查早期细胞分裂素反应，用细胞分裂素处理植物 30 分钟或 2 小时，然后进行基因芯片分析。我们的 GeneChip 数据的层次聚类分析表明，ARR7 过表达对各组细胞分裂素调节基因具有明显的抑制作用。特别地，除ARR22、AHK(拟南芥组氨酸激酶)1和AHK4之外的所有A型ARR的诱导均被ARR7抑制。细胞分裂素诱导的 12 个扩展蛋白基因中的大多数表达均被 ARR7 抑制，表明 ARR7 可能参与细胞扩增和植物发育。细胞分裂素对五种细胞分裂素氧化酶基因的上调受到 ARR7 的负面影响。我们的GeneChip分析表明，ARR7主要作为多种早期细胞分裂素调节基因的转录抑制因子，这些基因编码转录因子、信号递质、植物发育和细胞代谢，这可能是导致过度表达ARR7的拟南芥转基因植物对外源细胞分裂素敏感性降低的原因。
The type-A ARRs of cytokinin two-component signaling system act as negative regulators for cytokinin signaling except for ARR4, but the molecular mechanism by which the A-type ARRs regulate cytokinin signaling remain elusive. To get insights into the molecular function of A-type ARR in cytokinin response, we sought to find the components that function downstream of A-type ARR protein by investigating the effects of ARR7 overexpression on cytokinin-regulated gene expression with the Affymetrix full genome array. To examine early cytokinin response, plants were treated with cytokinin for 30 min or 2 h, followed by GeneChip analysis. The hierarchical clustering analysis of our GeneChip data showed that ARR7 overexpression had distinctively repressive impacts on various groups of the cytokinin-regulated genes. In particular, the induction of all A-type ARRs except for ARR22, and AHK(ARABIDOPSIS HISTIDINE KINASE)1 and AHK4 was suppressed by ARR7. Cytokinin-induced expression of most of 12 expansin genes were repressed by ARR7, indicating potential involvement of ARR7 in cell expansion and plant development. Up-regulation of five cytokinin oxidase genes by cytokinins was negatively affected by ARR7. Our GeneChip analysis suggest that ARR7 mainly acts as a transcriptional repressor for a variety of early cytokinin-regulated genes encoding transcription factors, signal transmitters, plant development, and cellular metabolism, which may be responsible for reduced sensitivity of Arabidopsis transgenic plants overexpressing ARR7 to exogenous cytokinins.